Pengxin controversially purchased the Crafar Farms in 2012 for $200 million, which was the largest-ever foreign acquisition of New Zealand land by value.
The Lochinver site is valued at $70 million and covers 13,800ha, compared to the 16 Crafar farms, which covered 8000ha.
Penxgin also owned a 74 per cent stake in 13 farms in the South Island.
Its buy-up of land has prompted a strong response from Opposition MPs, who say New Zealand should not be selling off its productive land to overseas interests.
Earlier today, Conservative Party leader Colin Craig revealed the company's plan to buy up more New Zealand land in a speech in Hastings.
He accused the OIO of keeping the deal secret until the election.
Speaking to a Grey Power meeting in Hastings this afternoon, Mr Craig said his party would block all substantial land sales to foreign buyers - a policy already proposed by New Zealand First, Labour and Greens.
Mr Craig said: "Although the deal has been agreed between the parties, and the Overseas Investment Office have received an application, the deal has not been disclosed to the public," Mr Craig said in a statement.
"We believe voters should be aware of what's going on behind closed doors, this is clearly an election issue."
Lochinver Station is on the Rangitaiki Plains, 32km southeast of Taupo. The sheep and beef farm was put up for tender early this year and has a capital valuation of $70.6 million, making it one of the most highly valued stations in the country.
The 13,800ha property is being sold by one of New Zealand's largest privately-owned companies, Stevenson Group, which has owned it for more than half a century.
Mr Craig said Conservatives would oppose all large, productive land sales and change the Overseas Investment Office criteria "so that our country is not sold up".
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"The National party waved through the Crafar Farms deal against our national interests and doubtless will do the same with Lochinver station.
"We are standing up for Kiwis who want this country to remain New Zealand owned," he said.
While Opposition parties who want to change foreign investment rules have not singled out countries, the issue first gained traction when the Crafar farms were sold to the Chinese company.
As a result, they have been accused by some of racial discrimination.